Predicting Patient Response to Lung Cancer Immunotherapy

A recent study found a potential method to analyze how a patient will respond to immunotherapy for non-small cell lung cancer (NSCLC).

The researchers looked specifically at the drug atezolizumab, which inhibits activity between programmed death 1 (PD-1) receptors expressed on immune cells and the programmed death-ligand 1 (PD-L1) found on the surface of tumor cells.

Researchers used positron emission tomography (PET) and the molecular compound fluorine-18 fluorodeoxyglucose (F-18 FDG) to track the potential of atezolizumab to increase immunity against NSCLC. FDG-PET allows the analysis of metabolic activity in cells.

Investigators specifically searched for increased activity that indicates malignancies, monitoring changes in activity both before and following 6 weeks of treatment. Included in the study were 138 patients with NSCLC treated with atezolizumab in 3-week intervals.

Researchers found that higher tumor volumes of FDG before treatment was associated with lower survival. They also found that increased tumor volume of FDG at 6 weeks is also associated with decreased survival.

Researchers believe that FDG-PET could potentially be used with chemotherapy as well to determine how a patient responds to treatment, according to the study.

"This study is the first to prospectively evaluate FDG-PET imaging in a phase II trial of lung cancer patients receiving the novel immune checkpoint inhibitor atezolizumab," concluded researcher Jill Fredrickson, PhD. "These findings help define the potential role of FDG-PET as a prognostic and predictive biomarker in the treatment of lung cancer with such immuno-therapeutics."

The study was presented at the 2016 Annual Meeting of the Society of Nuclear Medicine and Molecular Imaging.